There are numerous ratchet wrenches which have a pawl which is inserted in the top surface of the head of the wrench and which have dirt seals.
Slusar et al in U.S. Pat. No. 4,934,220 disclose a sealed ratchet wrench to reduce dirt contamination.
Arnold et al in U.S. Pat. No. 5,178,047 disclose a reversible ratchet wrench having a head portion with a drive member with teeth and a partially cylindrical pawl member having teeth which engage the teeth on the drive member. The stem of a lever is received in a cooperating bore in the pawl. A multi-sided shelf is formed on the stem, the shelf being received in the top of the pawl. A number of embodiments are disclosed and consideration is given throughout the reduction of the entry of dirt and other contaminants into the cavities.
However, further improvement is needed to facilitate more automated assembly of the tools and to improve the strength of the head of the wrench.